diff --git a/definitions/other.xml b/definitions/other.xml
index 7afc8f6..b930815 100644
--- a/definitions/other.xml
+++ b/definitions/other.xml
@@ -23,14 +23,18 @@
       <fraction n="0.045113" ref="6Li" />
       <fraction n="0.954887" ref="I" />
    </material>
-  
-<material name="LUNG20_AIR80" state="solid">
+
+   <material name="LUNG20_AIR80" state="solid">
       <D unit="g/cm3" value="0.209" />
       <fraction n="0.20" ref="G4_LUNG_ICRP" />
       <fraction n="0.80" ref="G4_AIR" />
    </material>
 
+   <!-- Borated HDPE 5% https://johncaunt.com/products/jcpe5/ -->
+   <material name="BoratedHDPE5pct" state="solid">
+      <D unit="g/cm3" value="1.04" />
+      <fraction n="0.05" ref="G4_B" />
+      <fraction n="0.95" ref="G4_POLYETHYLENE" />
+   </material>
 
-
-   
-</materials>
+</materials>
\ No newline at end of file
diff --git a/output/materials.xml b/output/materials.xml
index 8e9812a..dadc2bd 100644
--- a/output/materials.xml
+++ b/output/materials.xml
@@ -3184,6 +3184,11 @@
       <fraction n="0.20" ref="G4_LUNG_ICRP"/>
       <fraction n="0.80" ref="G4_AIR"/>
    </material>
+   <material name="BoratedHDPE5pct" state="solid">
+      <D unit="g/cm3" value="1.04"/>
+      <fraction n="0.05" ref="G4_B"/>
+      <fraction n="0.95" ref="G4_POLYETHYLENE"/>
+   </material>
    <material name="LiquidScintillatorBase" state="liquid">
       <D unit="g/cm3" value="1.03"/>
       <fraction n="0.085000" ref="G4_H"/>
diff --git a/output/rest.xml b/output/rest.xml
index 308b1c8..bac904c 100644
--- a/output/rest.xml
+++ b/output/rest.xml
@@ -3426,6 +3426,11 @@
       <fraction n="0.20" ref="G4_LUNG_ICRP"/>
       <fraction n="0.80" ref="G4_AIR"/>
    </material>
+   <material name="BoratedHDPE5pct" state="solid">
+      <D unit="g/cm3" value="1.04"/>
+      <fraction n="0.05" ref="G4_B"/>
+      <fraction n="0.95" ref="G4_POLYETHYLENE"/>
+   </material>
    <material name="Copper" state="solid">
       <D value="8.96000e+00" unit="g/cm3"/>
       <fraction n="1.000000" ref="Cu"/>